Abstract

Oralingestionofgreenteais a potentdietarysource of antioxidant polyphenols. These compounds are of interest as they may be able to provide additional protection to the body to help prevent the deleterious effects ofultravioletA andvisibleradiation (UVA/VIS) produced indirectly via reactive oxygen species (ROS) in sunlight exposed skin. A small clinical study was conducted in ten healthy adult volunteers. Samples of whole blood were obtained from each before and 30, 60 and 90 min followingingestionof three breakfast cups ofgreentea(540 ml in total) prepared in a standardised manner. Peripheral leucocytes were isolated from each blood sample and exposed to increasing periods of UVA/VIS irradiation in the laboratory (0, 9, 12 or 18 min). Alkaline single cell gel electrophoresis (the comet assay) was then conducted to determine the level ofDNAdamagein each sample from each individual. The findings support those of our previous pilot study and indicate that drinkinggreenteadid significantly reduce the genotoxic effects observed in peripheral blood cells 60 min followingingestionwhen artificially exposed to 12 min of UVA/VIS irradiation in the laboratory. It is postulated that this protection is afforded by the polyphenol compounds (known to be contained withingreentea) via scavenging or quenching of the damaging ROS induced by this form of light exposure. Furtherinvestigationshould consider whether thisdietary-induced protection could be extended to cells of the skin.